15 research outputs found
A catalog of Kazarian galaxies
The entire Kazarian galaxies (KG) catalog is presented which combines
extensive new measurements of their optical parameters with a literature and
database search. The measurements were made using images extracted from the
STScI Digitized Sky Survey (DSS) of Jpg(blue), Fpg(red) and Ipg(NIR) band
photographic sky survey plates obtained by the Palomar and UK Schmidt
telescopes. We provide accurate coordinates, morphological type, spectral and
activity classes, blue apparent diameters, axial ratios, position angles, red,
blue and NIR apparent magnitudes, as well as counts of neighboring objects in a
circle of radius 50 kpc from centers of KG. Special attention was paid to the
individual descriptions of the galaxies in the original Kazarian lists, which
clarified many cases of misidentifications of the objects, particularly among
interacting systems. The total number of individual Kazarian objects in the
database is now 706. We also include the redshifts which are now available for
404 galaxies and the 2MASS infrared magnitudes for 598 KG. The database also
includes extensive notes, which summarize information about the membership of
KG in different systems of galaxies, and about revised activity classes and
redshifts. An atlas of several interesting subclasses of KG is also presented.Comment: 15 pages, 5 figures, 1 table, Accepted in Astrophysics, Vol. 53, No.
1, 2010 (English translation of Astrofizika
Building Information Modelling (BIM) : a summary of some UK experiences as guide to adoption in Nigeria
Building information modelling (BIM) is a term that has been echoed around the world by researchers and practitioners alike. This is a new methodology (essentially electronic capture and focussed, timely distribution of relevant data) of project delivery that improves efficiency and quality of work. Although the word 'building' is used, BIM is equally applicable to civil engineering, utilities and infrastructure projects. Also, the word 'modelling' applies to the broad spectrum of process application not simply models produced by 3d software packages. The most important element in BIM is the 'information' and its beneficial capture and repeat usage. Every sector of the world economy is just looking for ways to produce more with fewer resources or making best use of the resources available. This paradigm shift has brought about the adoption of BIM in the construction industry. This paper will define BIM in simple terms; highlight its benefits and barriers; rationalise its workability, maturity levels and general ideas that it is based upon. The paper will also articulate some actual experiences from the UK at both the government and organisational level and the challenges overcome and some benefits achieved. Just like any other technology or methodology, BIM relies on collaboration for its successful implementation. This collaboration will create an avenue for construction teams to produce and make use of consistent unambiguous information, which will improve the overall efficiency in project delivery. For many people the question still remains. Will this be a solution to the all the problems in the industry? Or will it only solve particular problems? Just like every technology using it correctly will definitely yield benefits. Governments in many countries have recognised the usefulness of BIM and have intervened to make its implementation possible. As a developing country, Nigeria should not be far from making such efforts. There is need for construction industry to take proactive steps to overcome its problems. BIM implementation may not be a panacea to all the problems in the construction industry but it will surely make it better. Construction professionals may look at this idea with scepticism echoed, although it is now being overcome in countries adopting BIM. The earlier they realise that BIM will be the future of the industry the better
Synthesis, molecular modeling and biological evaluation of new benzo[4,5]thieno[3,2-b]pyran derivatives as topoisomerase I-DNA binary complex poisons
Frictionless contact of a rigid punch indenting an elastic layer having piezoelectric properties
Transformation of Lignocellulosic Biomass to Cellulose-Based Hydrogel and Agriglass to Improve Beans Yield
Search for the standard model Higgs boson at LEP
The four LEP Collaborations, ALEPH, DELPHI, L3 and OPAL, have collected a total of 2461 pb(-1) of e(+)e(-) collision data at centre-of-mass energies between 189 and 209 GeV. The data are used to search for the Standard Model Higgs boson. The search results of the four Collaborations are combined and examined in a likelihood test for their consistency with two hypotheses: the background hypothesis and the signal plus background hypothesis. The corresponding confidences have been computed as functions of the hypothetical Higgs boson mass. A lower bound of 114.4 GeV/c(2) is established, at the 95% confidence level, on the mass of the Standard Model Higgs boson. The LEP data are also used to set upper bounds on the HZZ coupling for various assumptions concerning the decay of the Higgs boson. (C) 2003 Elsevier B.V. All rights reserved
Precision Electroweak Measurements on the Z resonance.
We report on the final electroweak measurements performed with data taken at the Z resonance by the experiments operating at the electronâpositron colliders SLC and LEP. The data consist of 17 million Z decays accumulated by the ALEPH, DELPHI, L3 and OPAL experiments at LEP, and 600 thousand Z decays by the SLD experiment using a polarised beam at SLC. The measurements include cross-sections, forwardâbackward asymmetries and polarised asymmetries. The mass and width of the Z boson, mZ and ÎZ, and its couplings to fermions, for example the Ï parameter and the effective electroweak mixing angle for leptons, are precisely measured: The number of light neutrino species is determined to be 2.9840±0.0082, in agreement with the three observed generations of fundamental fermions. The results are compared to the predictions of the Standard Model (SM). At the Z-pole, electroweak radiative corrections beyond the running of the QED and QCD coupling constants are observed with a significance of five standard deviations, and in agreement with the Standard Model. Of the many Z-pole measurements, the forwardâbackward asymmetry in b-quark production shows the largest difference with respect to its SM expectation, at the level of 2.8 standard deviations. Through radiative corrections evaluated in the framework of the Standard Model, the Z-pole data are also used to predict the mass of the top quark, , and the mass of the W boson, . These indirect constraints are compared to the direct measurements, providing a stringent test of the SM. Using in addition the direct measurements of mt and mW, the mass of the as yet unobserved SM Higgs boson is predicted with a relative uncertainty of about 50% and found to be less than at 95% confidence level